Bambu Lab P1S Chamber Exhaust Scrubber "Snorkel"

13 January 2024: Included an upgraded Filter Module (P1SFilterModuleHighVolume.stl) that holds about 30% more pellets than the old one with no changes to the outer profile. Also included a STEP file of the whole thing for adjustments or remixes (using the high volume filter module). Updated description to have clickable links to parts from Amazon.

This is a chamber exhaust air scrubber for the Bambu Lab P1S.  It helps reduce VOCs and particulates from the chamber exhaust when printing, especially in low ventilation areas. The assembly fits to the back of the machine with a duct that connects magnetically overtop the chamber fan outlet, and then a bracket/standoff which magnets to the top lip of the printer. 2 inline computer fans pull air up through the filters and out the top of the machine. The whole assembly adds 72mm of depth to the back profile of the printer.

Inspired by the renown BentoBox chamber filter, and my other scrubber for the xTool F1 with which it shares many design features, but has a simpler electrical design (no soldering or wire crimping).

The device consists of 3 primary modules connected together with M4 nuts/bolts and magnets with an O-ring seal between each. The plenum and fan modules are designed with a 20mm offset to fit around the PTFE tubing, power cables, and filament management devices on the back of the printer (see photos).

Plenum: Air intake with magnets that fits over the chamber exhaust outlet.

Filter Module: Uses a robovac HEPA filter, followed by a box of activated carbon pellets. Carbon pellet box has a lid that slides on/off for refill when needed. Robovac filter presses into a recess in one side. The filter module can be oriented any way, though I have it set up with HEPA on bottom (closest to Plenum).

Fan Module: Houses 2x inline 40mm fans to pull air through the HEPA filter and carbon pellet bed, and out the top of the unit. Fans are separated by a stator vane and press-fit into the top of the fan module during assembly. The fans are powered by an off-the-shelf 2-fan USB speed controller linked below, and power cables fit inside an electronics cavity adjacent to the fan ‘shaft’. I highly recommend using the linked Arctic fans to achieve the suction required to pull air through the filter media.

Printing:

Recommend printing one piece at a time unless you are very confident in your slicing/prep skills and performance of your printer. I printed all components on a Bambu Lab P1S using basic PLA and Polylite PETG as an interface layer for supports.

I printed the Fan Grille (stator vane) part at half speed to help with the thin vertical fin sections.

Settings: 0.4mm nozzle, 0.2mm layer height, 3 wall loops, 3 top/bottom layers, 15% cubic infill.  Supports should only be needed for the Filter Module and Fan module. I used a 5deg threshold angle for support generation on both parts to only catch the 100% bridge sections like the mesh at the bottom of the carbon filter (other overhangs do not need support). 6+mm outside brim on all major parts helps bed adhesion.

Assembly:

The plenum and filter module should be fairly self-explanatory to assemble. Press-fit M4 nuts into the hex-shaped holes in the flanges on the filter module. The fan module and plenum each have a deeper recess for O-rings to press into. Cut O-ring material to fit each recess and use CA glue to attach the material end-to-end.  Let the glue dry, then press each O-ring into the recess (gland). Magnets press into holes at each interface, a dab of CA glue helps hold them in place in each hole. Ensure magnet poles are matched so pieces snap together properly.

Guiding the power cable down the ‘slot' provided and pulling slack into the electronics cavity, press the first 40x28mm fans into the 40x40mm ‘fan shaft’ hole in the top of the fan module. This is an intentional interference fit and may require some pressure. During install, ensure both fans are oriented the same direction - to pull/blow air out the top of the device. After making sure the first fan is fully seated at the bottom of the 40x40mm shaft, drop the Stator Vane in. Follow this by threading the second fan's power cable through the provided hole, and guiding the cable down the slot as with the first fan, pressing the fan body into the hole until completely seated.  Caution: it is very difficult to remove the fans after installation. The loose end of each fan cable should be in the electronics box.

Connect fan cables to the speed controller, and test. Install the fan cover on the top of the fan module with 2 small sheet metal screws.  Install O-rings and magnets, the HEPA filter and carbon pellets into the filter module, slide on the filter cover, and assemble major modules using M4 bolts. Install the whole assembly onto the back of your Bambu Lab P1S. Use the switch on the speed controller, or a remote power plug to switch fans on/off as needed.

Additional parts and tools required:

• Qty (4) 14+mm M4 bolts
• Qty (4) M4 nuts
• Qty (2) 40x40x28mm high-pressure fans (https://www.amazon.com/dp/B09SB3Z6ND the 1400 to 15000RPM version)
• Required: Qty (4) 6mmx3mm circular magnets for attachment to printer (https://www.amazon.com/dp/B09TPJ2J5Y)
• Optional: Qty (16) 6mmx3mm circular magnets for module-to-module alignment (https://www.amazon.com/dp/B09TPJ2J5Y)
• Qty (4) 8mmx3mm (or smaller) circular magnets for the plenum interface with back plane of printer
• 2-fan USB speed controller (https://www.amazon.com/dp/B0C1W1TR38)
• 2A+ USB power adapter
• 2mm O-ring stock (https://www.amazon.com/dp/B00R0VW4S8)
• Qty (1) HEPA filter (https://www.amazon.com/dp/B0782T7L6P)
• Activated carbon pellets (https://www.amazon.com/gp/product/B0C795JTSM)
• Qty (2) small countersunk sheet metal screws to secure fan cover
• CA glue for magnets and O-rings.

I use this M4 bolt set: https://www.amazon.com/dp/B0B6J1SKZV

Disclaimer: This product is not endorsed by Bambu Lab. Using the scrubber may affect print quality or the printer's ability to hold temperature for particular types of filament. It can override the built-in chamber exhaust fan at certain settings (or when the fan is off). The alignment magnets are a bit extra and not completely necessary, though they do offer a very satisfying assembly experience. I have not done a lot of testing to gauge effectiveness, but in limited use it seems to make a difference. I have not tested this with an X1 or X1C, but if overall dimensions are the same it should work without issue.

Version History:

v1: Initial release.
v1.1 Added a high volume filter module.